7 results
Now showing1 - 7 of 7
- Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Impedance spectroscopy for multi-state analysis of dissolvable powders: determining layer thickness and moisture content(Elsevier, 2026-03-27); ; ; ; This study presents a novel methodology for applying Electrical Impedance Spectroscopy to analyze the electrical properties of dissolvable powders, when applied as a coating layer to quantify their thickness and moisture content. To address challenges posed by undefined geometries, powders were dissolved and applied as coatings on custom-designed Printed Circuit Board electrodes. Using sodium benzoate as a model material, the drying process was monitored in off-line measurements, revealing distinct transitions in electrical properties. Impedance and phase angle measurements effectively tracked moisture reduction during drying, while coating thickness and solution concentration also influenced conductivity. The findings demonstrate the potential of this approach for industrial applications, such as fluidized bed spray granulation, by enabling real-time monitoring of drying states.Publicationtype: Journal Article62 129 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Modelling the breakage of coated particles using discrete element and bonded particle methodIn recent years, particles have gained popularity as crash absorbers. To improve their mechanical properties, a coating layer can be applied. To predict the effect of this coating, a numerical model must be developed. For this purpose, the present study employs the discrete element method, extended by the bonded particle method, using both high- and low-fidelity approaches. In this framework, a single physical particle is modelled as a cluster or agglomerate of smaller particles bonded together. To identify the parameters involved, a sensitivity analysis is performed, followed by optimisation using the particle swarm algorithm, with calibration based on uniaxial single particle compression tests. Once an optimised parameter set is obtained, the models are validated against multi particle compression test results. The outcomes of this study demonstrate the potential of the proposed methodology for simulating large-scale compression tests of coated granular materials.Publicationtype: Journal Article26 20 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Influence of spray parameters on injected droplets and product properties in fluidized bed spray granulationLiquid injection is one of the, if not the most, critical steps in fluidized bed spray granulation as the product quality as well as the overall process stability can be massively influenced by the associated parameters. Therefore, this study aims to correlate spray parameters to the spray pattern and droplets produced from the nozzle and the resulting granule properties. First, the effect of spray variables on spray angle and droplet size and velocity was analyzed, revealing the spray air pressure as crucial parameter. Afterwards, spray agglomeration experiments were conducted according to a statistical experimental plan varying several process-related parameters in addition to the nozzle set-up. The product particle size distribution was shown to be impacted by a complex combination of the investigated variables with the liquid spray rate, spray and protection air pressure, and fluidization air flow as main influences.Publicationtype: Journal Article62 50 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , CFD-DEM modeling for optimized liquid distribution in fluidized bed spray granulation(Elsevier, 2024-09-19); ; ; ; In this work, CFD-DEM simulations of two different fluidized bed granulator geometries were performed, aiming to provide an insight into how the injected liquid behaves within the particle bed and thus an overall better understanding of the granulation process itself. Simulation results were evaluated regarding the fate of sprayed droplets, e.g. deposition on a particle, elutriation from fluidized bed, or collision with apparatus walls. For the deposited droplets, the particle–droplet collisions were tracked in order to obtain a locally resolved deposition rate. Spray parameters as well as geometric specifications of the nozzle setup were varied, investigating a broad range of different process conditions. By optimizing apparatus design, especially the air inlet, an even distribution of the liquid droplets within the fluidized bed and overall higher deposition rate can be achieved and a stable steady state with a well-defined spray zone is reached within a broad range of varied spray parameters.Publicationtype: Journal Article49 58 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Simulation of the mechanical behaviour of coated particles using DEM‐BPMIn previous years, research into the use of granular media as crash absorbers in a ship double hull has led to an increased interest in further optimisation to improve their energy absorption. One way is to add a coating layer on the outside surface of these particles. This work provides an introduction to the numerical modelling of coated particles to simulate their crushing behaviour. Depending upon the type of coating material, the compressive behaviour differs. Therefore, a sound methodology needs to be developed. For that purpose, the discrete element method in combination with the bonded particle method was utilised using the open‐source code MUSEN. The bonded particle method helps to simulate the crushing behaviour of coated particles. However, for this high‐fidelity model, the number of parameters needs to be reduced and afterwards optimised. A sensitivity analysis is performed for that objective followed by optimisation using particle swarm algorithm. The results illustrate a good approximation of the experimental force‐displacement curve by the optimised model on a uniaxial single particle compression test.Publicationtype: Journal Article16 51 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Influence of nozzle parameters on spray pattern and droplet characteristics for a two-fluid nozzleIn this study, a two-fluid nozzle, as, e.g., used in fluidized-bed or spray drying applications, is comprehensively characterized regarding the spray pattern and droplet size. To analyze the spray cone, the spray cone angle and the radial mass distribution of the nozzle were measured at varied liquid flow rate, spray air pressure, liquid insert bore diameter, and air cap position. Additionally, droplet size distributions were recorded at different spray settings. In general, the overall spray cone and single droplets are significantly influenced by the spray parameters, especially the spray air pressure, as well as the nozzle geometry.Publicationtype: Journal ArticleScopus© Citations 3 169 207 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Spray coating of cellulose aerogel particles in a miniaturized spouted bed(Springer, 2021-07-04); ; ; ; Aim of this work is to apply protective and homogeneous shellac coating layers on the surface of hydrophilic open-pore cellulose aerogel particles with low densities ≤ 0.1 g/cm3 and high specific surface areas in the range of ~ 400–450 m2/g while keeping the aerogels’ microstructure intact during processing. For this purpose, an innovative miniaturized spouted bed setup was used. Successful process settings for application of enclosed films on aerogel surfaces without intrusion of coating material into the pores were determined. Precise control of coating layer thickness in the range of 10–50 µm was achieved due to variation of coating solution amount without agglomeration and clogging events occurring during processing. Comparison of bulk densities and specific surface areas before and after coating proved the intactness of the porous structure. Coating of particles loaded with vanillin led to controlled release, enhancing release half-life times from 20 to 1600 min. Overall, a successful strategy for coating of organic low-density aerogels was developed.Publicationtype: Journal ArticleScopus© Citations 13 217 261